1. Field of The Invention
The present invention generally relates to a portable apparatus for removing and remotely filtering contaminated liquids or dirty cleaning fluid solvents and then returning by continuous recirculation or recycling the resulting clean liquids and solvents to reservoirs of machinery, such as internal combustion engines and industrial parts washers, without need for completely emptying said liquid from the machinery reservoir.
More particularly, the present invention pertains to a portable apparatus comprising a motor, pump and flexible conduit hose arrangement in communication with a specially designed filtering cartridge within a filtering canister for remotely withdrawing said contaminated liquids and solvents from a .machinery reservoir and forcing by pressure the fluid through said remote filtering canister which provides for collection of dirt, grit, soil, grease and particulate matter within the canister filtering cartridge, and thereby further allowing clean liquid or fluid solvent to be continuously returned by recycling to a machinery liquid reservoir while said machinery is either being used, or without emptying the liquid therefrom, and thereby circumventing any need to halt an industrial production line activity or transfer dirty fluids to a storage tank for mere cleaning and replenishing of the liquid or fluid solvent therein.
Even more specifically, the present invention deals with an improved arrangement of a coiled fibrous filtering cartridge, preferably of cellulose, positioned within its filtering canister which has been specifically designed to work on an "reverse vertical-flow" principle to maximize surface area contact between the filtering cartridge and a variety of contaminated liquids and solvents commonly used in modern machinery, refrigeration, air-conditioning, food processing and even highly corrosive non-aqueous toxic cleaning fluids in industrial parts washers.
The portability of the hereinafter described apparatus of the present invention, along with its versatility for providing continuous cleaning by recycling a variety of contaminated liquids and toxic solvents through an improved filtering cartridge within its improved canister design, is believed to be an advantage over the prior art.
2. Description of The Prior Art As it is perhaps well known, modern industrial machinery, internal combustion engines, electrical equipment, food processing apparatus and parts washers, often utilize a variety of liquids or solvents for the purpose of lubrication, heat transfer and cleaning which can range from common motor oil for lubrication in an automobile engine to toxic chlorinated hydrocarbons in a parts washer for cleaning electronic semi-conductor components. These non-aqueous liquids and solvents with use over time become dirty and contaminated with dirt, grime, grease, grit and particulate matter and need to be replaced by clean fluids.
In bygone years, and before enactment of present environmental regulations, it was not uncommon to find that dirty and contaminated non-aqueous liquids, solvents and their cleaning fluid mixtures were merely disposed of in a sanitary sewer, or, for that matter, simply dumped on the ground. However such practice today is clearly unacceptable, if not unlawful.
Today, one method of disposing of non-aqueous liquids and fluid solvents involves their total removal and transportation to a disposal site, which is very inconvenient and expensive to say the least, but, moreover, there is an additional environmental concern that such toxic dump sites are fast becoming overwhelmed with waste. Accordingly, any means of prolonging the life efficiency of said liquids and fluids would be of both economic and environmental importance.
Another approach to the present problem of disposing of dirty and contaminated non-aqueous liquids or fluid solvents is by remediation. That is to say, that the fluid is removed and collected from a machinery reservoir for transport to a chemical distillation and recovery plant where the fluids are separated, purified and resold. The impurities, when separated and rendered harmless, are then disposed of normally.
Of course, disposal costs whether by lawful dumping or remediation are but one major consideration in any industrial application, since there is always additional down-time of machinery or a production line while any fluids are removed from their reservoirs and replenished, and it only follows than any innovation or technique which can prolong life of these fluids or allow for their remediation without emptying their reservoirs would have a positive economic benefit to that industry in the form of lower costs, less down time, and, perhaps an additional bonus for the environment.
The prior art reveals descriptions of external filtering apparatus and filter canister arrangements for specific purposes, but none are known to provide the combined benefits of the present invention.
For example, in U.S. Pat. No. 4,591,434 (1986), Prudhomme describes a remote dual filtering apparatus for filtering and purifying contaminated oil used in deep-fat fryers. His presumably portable apparatus generally comprises a remote tub divided into an upper and lower section, said upper section containing a canister filter in communication with a flexible conduit through which oil from an external fat fryer is conveyed by a pump through said canister filter and into the bottom portion of his tub for accumulation therein and thereby draining the fat fryer. The cleansed oil may be then returned to the fat fryer by reversing flow of the pump.
Although it would appear at first glance that the Prudhomme apparatus employs the same principle as the present invention, it should be pointed out that Prudhomme requires complete drainage of the external fat fryer reservoir and accumulation in its lower tub-section while the present invention provides for continuous circulation and recycling of a remote reservoir fluid thereby obviating any need to drain the reservoir, which is believed to be one major improvement over the prior art.
Moreover, the filtering canister arrangement of Prudhomme performs oppositely of the present invention in that the direction of his fluid flow is upwardly through the filter cartridge, while fluid flow of the present invention is downwardly through the filtering cartridge or a "reverse vertical flow" which is believed another improvement to minimize a common problem of fluid "channeling" known to occur in other prior art filtering apparatus.
As a further example of prior art filtering canister arrangements, in U.S. Pat. No. 4,869,820 (1989), I last described an axial or "opposed-flow" filtering apparatus composed of co-axially stacked coiled rolls of filtering paper separated by a screened conduit for axially directing fluid flow from the interior of the filter cartridges inwardly to an outlet means and thereby improving upon control of flow with respect to previous art employing single paper roll filter cartridges and filtering canisters as described in U.S. Pat. Nos. 4,575,422; 3,572,509; 3,481,478; 3,319,790. Although my improved dual "opposed" or axial flow filter apparatus also preferably utilized common tissue paper rolls for filtration of automotive oil as did the other aforementioned single roll filters, none of these filter cartridges nor canister designs were found to be satisfactory for filtering a wide range of non-aqueous liquids and solvents with different viscosities and even some with reactivity to the paper filter cartridge itself. In other words, the known prior art filtering apparatus, filtering cartridges and their canister arrangements have all been designed to accommodate a particular and specific kind of liquid, rather than a broad range of liquids with different viscosities and chemical reactivity. This difference is believed to be a major advantage of the present invention over the prior art.
As yet one further comparison, with respect to known prior art non-aqueous filtration systems, concerns application of the present invention to cleaning fluid solvents in industrial parts washers, such as those described in U.S. Pat. No's. 3,890,988 and 3,378,988. Because these parts washers can be employed to clean a variety of industrial parts ranging from greasy automobile parts to electronic semi-conductor components, it is also easily seen that they may also utilize a wide range of solvents having different physical and chemical properties other than those of automotive lubricating oil. In fact, solvents most widely used as cleaning fluids in parts washers today are chosen from any group of chlorinated hydrocarbons (such as carbontetrachloride and trichloromethane), fluorinated hydrocarbons (such as the FREONS), petroleum distillates (such as petroleum ethers), aromatic hydrocarbons (such as toluene and naptha), ketones (such as acetone), alcohols (such as methanol), and proprietary mixtures thereof. Thus, the prior art filtering apparatus have not addressed remote filtration and continuous recycling of a variety of non-aqueous contaminated liquids and toxic solvents with different viscosities and with regard to efficiency of the filtering cartridge.
For example, it is well known that viscosity is that physical property of a liquid giving it resistance to flow, at a particular temperature, and often measured in centipoises (cp) with common automotive motor oils having a viscosity of approximately 30 cp and acetone of approximately 0.3 cp at 20 degrees centigrade. Therefore, any apparatus for remotely filtering and continuous recycling of contaminated liquids in a variety of machinery should be able to accommodate a wide range of liquids with viscosities ranging over 100 cp. Moreover, the prior art apparatus previously cited does not address any adverse chemical reaction between said various fluids and previously described paper tissue roll filters, some of which are known to be degraded and destroyed or exhibit channeling therein by contact with non-compatible solvents.
Accordingly, it is a General object of the present invention to provide a portable apparatus for remotely filtering contaminated liquids from a variety of machinery reservoirs by continuous recycling or recirculation of the liquid between said reservoir and apparatus without need to completely drain the reservoir.
It is another object of the present invention to provide an improved coiled fibrous cellulose filtering cartridge in combination within an improved filter canister design for specifically and efficiently filtering a variety of contaminated liquids having viscosity ranging from 0.3 to 40 centipoise at 20 degrees centigrade, while withstanding chemical attack by caustic and toxic solvents.
These and other advantages are achieved by the present invention.